Proton vs. Electron

Proton vs. Electron

Introduction

Every atom in the universe consists of proton, electron and neutron. What we see around us is the combination of these particles in different pattern and amount. As far as we know, these particles are composed of basic elementary particles called quarks.

The universe that we have seen is all composed of matter except for few antimatter that we managed to produce in lab for few seconds or milliseconds. Every gram of any matter consists of million of billions of atoms and every atom has several electrons, protons and neutrons. So, our universe has uncountable numbers of these particles. Let’s look upon our topic: proton vs. electron.

Discovery

Electron was discovered by Joseph John Thomson (J. J. Thomson) in 1897 while studying cathode rays while proton was discovered by Ernest Rutherford in 1911 by using gold foil experiment.

Composition

Electrons are regarded as fundamental particle and are not made up of any other particles while protons are made up of quarks. The combination of two up and one down quarks forms proton.

Structure of Proton
Figure showing how proton is formed by the combination of tow up quarks and one down quarks
Structure of Electron
Figure showing the elementary structure of electron

Symbol

Electrons are denoted by e or β while protons are denoted by p, p+, N+, or 11H+.

Antiparticle

Antiparticle of electron is anti-electron and that of proton is anti-proton.

Classification

Electrons fall under the Lepton group while protons fall under Hadron group and Baryon sub-group.

Mass

Electrons are very light particles while protons are heavier ones. Mass of an electron is 9.1*10-31 kg and that of proton is 1.67*10-27 Kg.

Charge

Electrons are negatively charged particles while protons are negatively charged ones. Charge of an electron is -1.6*10-19 C and charge of a proton is +1.6*10-19 C. Charge on a proton may be illustrated as follows:

Proton is the combination of two up and one down quarks. Each up quark has +2/3 C charge and each down quark has -1/3 C charge. So this combination gives the net charge of proton as:
+2/3 + 2/3 -1/3 = +1

Similarly, electron is the combination of one up and two down quarks. Each up quark has +2/3 C charge and each down quark has -1/3 C charge. So this combination gives the net charge of proton as:
-2/3 – 2/3 + 1/3 = -1

Specific Charge

Specific charge the ratio of charge to its mass. We know that mass of electron is less than that of proton and both have charge of unit magnitude. Since specific charge is inversely proportional to the mass, electron has higher value of specific charge.

The value of specific charge of electron is -1.758*1011 C/Kg and the value of specific charge of proton is +9.576*107 C/Kg.

Location

Electron is located in an orbit around the nucleus and revolving around it while proton is located inside the nucleus, bounded with neutrons and other protons.

Figure showing location of proton and electron in nucleus
Proton and Electron in an atom

Existence in an Atom

Protons are located inside nucleus and are held together by strong binding energy between nucleons while electrons revolve around nucleus (according to old concept) by the help of electromagnetic force.

Baryon Number

Baryon number is a quantum number that is assigned to the elementary particles. Its value is +1 for all baryons, -1 for all anti-baryons and 0 for non-baryons. So, protons, being a baryon has baryon number +1 and electron being a non-baryon has baryon number 0.


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